What is Job Control Language (JCL)?

JCL (Job Control Language), just like COBOL, is not a language used to create any OS, but rather to run jobs in a mainframe environment. In that aspect, COBOL, while controlled by JCL in order to compile and its binaries to run, drove the innovation of mainframes.

JCL was released in 1965 by IBM for the IBM OS/360 system as a means to run any group of commands in a specific order (batch). It soon became the default means to compile and/or run COBOL compiled binaries. For many users, JCL became closely related to COBOL and not a language to write batches.

For batching in a mainframe environment, I preferred REXX (Restructured Extended Executor), which IBM released in 1979, because it is similar to shell scripting or DOS batching. As a matter of fact, I used to have fun calling REXX scripts from my PROFILE EXEC file (similar to an AUTOEXEC.BAT in DOS) when logging in to start accounts and printers as the operator in z/VM. As the saying goes, all good things come to an end and the organization I work for moved production to a PeopleSoft (Oracle).